If you have aircrafts that involve of on board's personal you must insert it on the aircraft (more or less like the pilots). If there isn't on board's personal on your aircraft ,the aircraft can't do compensated flights. For the trasfer isn't necessary the on board's personal but is enough the pilot's presence. In the personal's section you can hire or lay off the on board's personal. It isn't possible lay off on board's personal that is on a plane but first you must "come down". Any on board's personal have a fixed price of 300 euro for week.